The personal computer is in crisis, and getting little help from Microsoft Corp.'s Windows 8 software once seen as a possible savior.

Research firm IDC issued an alarming report Wednesday for PC makers such as Dell Inc. and Hewlett-Packard Co., saying world-wide shipments of laptops and desktops fell 14% in the first quarter from a year earlier. That is the sharpest drop since IDC began tracking this data in 1994 and marks the...